1. Technical Field
This invention relates to separation and recycling of abrasive steel blast material from entrained contaminates, including paint dust and rust encountered during the blasting process in cleaning and preparing a variety of surfaces in the industry.
2. Description of Prior Art
Prior art devices and processes have been developed that utilize a variety of fixed and mobile separation apparatus that clean and separate waste materials from used shot blast recycling for reuse. Examples of prior art patents can be seen as follows: U.S. Pat. Nos. 3,716,941; 3,954,374; 4,449,331; 4,773,189 and 4,943,368. Additional patents by applicant are U.S. Pat. Nos. 5,185,986; 5,468,147; 5,520,288; 5,695,385 and 6,514,128.
In U.S. Pat. No. 4,773,189 a separation system is disclosed for polymer blasting media which is cited to show multiple tasks separation systems in which contaminated blast products are collected, processed and reused in a continuous manner. The hazardous contaminates being directed to separate disposable storage units within the process.
U.S. Pat. No. 3,716,946 uses a recirculation close system with air separation as the initial separation with a secondary magnetic separator for removal of ferrous shot from the remaining non-ferrous contaminates.
U.S. Pat. No. 4,449,331 shows shot blasting machinery used in communication with a blast cabinet module. The device is characterized by a feed and lift conveyor recirculating system in communication with the blast cabinet for transportation of spent contaminated shot to the top of a vertical separation stack.
U.S. Pat. No. 4,943,368, a non-metallic abrasive blasting material recovering process is disclosed having multiple steps of size classification, ferro-magnetic separation, gravity separation, electrostatic separation which is used in separation of non-conductive paint from conductive blasting media.
U.S. Pat. No. 3,934,374 a sand blast reclamation system is disclosed using an air wash separator feeding a blast wheel. Contaminated air is directed to a fabric dust collector for filtration. A sand separator is positioned above the magnetic separator supplying usable sand back to the blast wheel via an infernal elevator belt.
U.S. Pat. No. 2,810,991, an abrasive blasting apparatus is disclosed that provides for a movable self-contained blasting and separation unit that recovers the spent contaminated shot as it is used and recirculates same through a separation process. The separator uses an air driven grit reclaimer in combination with a transfer chamber.
In applicant's U.S. Pat. No. 5,185,968 a mobile separation system is disclosed wherein a multi-step magnetic and air wash separation is used.
U.S. Pat. No. 5,468,174 is directed to a recyclable abrasive blasting system having a classifier with auger screen separators and air wash.
U.S. Pat. No. 5,520,288 claims an abrasive grit material recovering system having a rotary screen separator, a magnetic separator, and an air wash on a mobile platform.
U.S. Pat. No. 5,695,385 shows a recyclable abrasive blasting system method using multiple auger screen separation and interconnected air wash to achieve particle separation.
Applicant's Patent 6,514,128 discloses a separating abrasive blasting media from debris using a rotary drum separator with different size gradation interior surfaces.